Apparatus for case hardening glass



Oct. l, 1935.

R. A. MILLER ET AL APPARATUS FOR CASE HARDENING GLASS Filed Dec. 4, 1934 2 Sheets-Sheet 1 J OBO; o o

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APPARATUS FOR CASE HARDENING GLASS IN VEN TORD RAJVILLER By Ly. 5l-.M2M

A TORNEYS.-

Patented ocr. 1, 192.5

Roberta. `Miller and Lloyd v. Black, Tarentm,

, Pa., assignors to Pittsburgh Plate Glass Company, a corporation of Pennsylvania Application Decemberd, 1934, Serial No. 755,937

,. t `4 Claims. (ci. 49414) Theinvention relates to apparatus Vfor case hardening glass and particularly to the means for supporting the glasssheets during the heating and chilling operations. In an operation of this kind, the glass is 'suspended in a vertical plane from its upper edge, ordinarily by clamps carried by a horizontal supporting bar, and'in the case of large 'sheets difculty is experienced in keeping the points of support in horizontal alignment incident to the warping of the supporting bar caused by the extremes of temperature to which the bar is exposed. As aresult, the horizontal edges 'of the glass sheets are distorted and made irregular since the sheets are heated to a temperature approximating the softening point, and the softening of the glass permits the distortion due to the very considerable weight of the glass. The

-object of the invention is to provide supporting means which will overcome the diiculty as to distortion so that the upper and lower edges of the case hardened sheets are substantially straight and free from distortion. Briefly stated, the defrom -being warped out ofalignment. One emsired object is accomplished by making the supporting bar in sections,`each supported for free independent movement, and by providing means for preventing the hangers which support the bars bodiment of the invention is illustrated in the accompanying drawings, in which:

Figure 1 is aside elevation. Fig. 2 is a partial section andv partial end view. And'Fig. 3 is a section Vonthe line )1I-III of Fig. 1.

Referring to the drawings, I is thel furnace through which the glass sheets are carried in order to heat them preliminary to the` chilling operation, such furnace being provided with a -slot l along its Cupper end; and 3 is a monorail 'extending longitudinally of the slot thereabove. This monorail carries a pair of trolleys 4 and 5 ,having the wheels 6, which ride on the fianges of the rail. These trolleys carry a rigid frame made-up of the angles 1, 1 and from this frame depends the series of hangers 8, 8, 8 adapted t to extend through the slot 2, as indicated in Fig. 2. Asbestos sheets 9, 9 carried by the top of the furnace serve as a closure for the slot 2 and yet permit the ready passage of the hangers.

yThe lower portion of each hanger is made up of a pair of plates I0,` III bolted or riveted to the lower ends of the member 8 and spaced at theirl lower ends by the pairs of blocks II and I2 secured by the bolts I3 and I4. Extending through the hangers vbetween the plates I0, IIJ and resting on the blocks [I3 is a stiiening bar I5. This bar is free to move endwise with respect to each o1' the hangers and serves to keep them in alignment and prevent any warping of the hangers whiche would tend to throw them out of alignment.

' Supported upon a series of blocks I2 at the' extreme lower ends of the hangers are the tong `5 the hangers, the opposing ends of the bars I6 and I1 being spaced in the middle hanger, as indicated at I8. This freedom of movement reduces the 10 tendency of the bars to warp, and in order to still further reduce this tendency, the bars are slotted, as indicatedat I9. Each of the tong bars carries a series of collars or loops 28 to -whose lower 4ends are attached the links 2l (Fig. 2). 15 These links are attached at their other ends to the handle 22 of the tongs 23, such tongs being provided with the usual pins 24 for engaging `the edge of the glass sheet. The weight imposed by the glass sheet tends to close the tongs and thus give the necessary gripping action upon the edge of the sheet.

The use ofthe supporting means for the glass sheets, as illustrated and described, gives a support which evenfwith verylarge sheets avoids any 25 substantial-deformation'o'f the upper 'and lower edges thereof. "Any vertical warping in the tong bars is reduced to a minimum incident to their relatively short length and their freedom to expand, and the stiifening bar I5 prevents any 30 lateral deformation of the edge of the sheet, as the hanger plates' 8 are maintained by this expedient' in substantial alignment at all times. The support 1, 1, to which vthe upperends of the hangers are attached, lies well outside of the heat of the furnace'so that this member is not subject to deformation.

In operation, the glass sheet is supported upon the apparatus' outside the furnace and -is then 40 moved along through the furnace --which is in the, form of a tunnel kiln of gradually increasing temperature. When' the glass has reached a proper temperature for chilling, it is removed through the outlet end of the furnace, the general 4'5 operation being well known in the art;

What we claim is: u

1. Apparatus for case hardening glass sheets comprising a longitudinally extending overhead support, a series of spaced hangers depending Yfrom the support, a series of supporting bars placed end to end and supported at each end in lone of the hangers' so that suclrends are free to adaptedptolengage the edge of the glass sheet I which is to be case hardened.

2.' Apparatus for case hardening glass sheets comprising a longitudinally extending overhead support, a series of spaced hangers depending from the support, a series of supportingbars placed end to end and supported at each end in one of the hangers so that such ends are free to move through the hangers, and a plurality of spaced gripping members carried by each bar ande one of the hangers so that such ends 'are free tomove through the hangers, a horizontal stiifening bar extending the length of the series of hangers above such bars and engaging such hangers and holding them in alignment but free to move endwise with respect thereto, and a plurality of spaced gripping members carried by each supporting bar, and adapted to engage the edge of the glass sheet which is to be case hardened. A

4. Apparatus'for case hardening glass sheets 5 comprising a longitudinally extending overhead support, a' series of spaced hangers depending from the support, 'and each comprisingra pair of, parallel plates having supporting Eabutments at their lower ends, a series of supporting bars placed lo end to end andsupported at each end in one of the hangers on said abutments so that such ends are free to move endwise on the abutments, a

-hozontalsti'ening bar above the supporting bars extending between the plates comprising the 15 hangers and supported thereby but free to move endwise with respect to the hangers, and a plurality of spaced gripping members carried by each supporting bar, and adapted to engage Athe edge of the glass sheet which is to be case hardened. 20

ROBERT A. MILLER. LLOYD V. BLACK.V 

